• The Korean Journal of Physiology and Pharmacology
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• 제8권3호
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• pp.161-165
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• 2004

Exogenous carbon monoxide (0.2%) increases L-type calcium $(Ca^{2+})$ current in human jejunal circular smooth muscle cells. The stimulatory effect of carbon monoxide (CO) on L-type $Ca^{2+}$ current is inhibited by pre-application of L-NNA, a classical competitive inhibitor of nitric oxide synthase (NOS) with no significant isoform selectivity (Lim, 2003). In the present study, we investigated which isoform of NOS affected CO induced stimulation of L-type $Ca^{2+}$ current in human jejunal circular smooth muscle cells. Cells were voltage clamped by whole-cell mode patch clamp technique, and membrane currents were recorded with 10 mM barium as the charge carrier. Before the addition of CO, cells were pretreated with each inhibitor of three NOS isoforms for 15 minutes. CO-stimulating effect on L-type $Ca^{2+}$ current was partially blocked by N-(3-(Amino-methyl) benzyl) acetamidine 2HCl (1400W, an iNOS inhibitor). On the other hand, 3-bromo-7-nitroindazole (BNI, a nNOS inhibitor) or $N^5-(1-Iminoethyl)-L-ornithine$ dihydrochloride (L-NIO, an eNOS inhibitor) completely blocked the CO effect. These data suggest that low dose of exogenous CO may stimulate all NOS isoforms to increase L-type $Ca^{2+}$ channel through nitric oxide (NO) pathway in human jejunal circular smooth muscle cells.

• E2M - 전기 전자와 첨단 소재
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• 제7권2호
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• pp.138-144
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• 1994

Electrical conduction phenomena of $C_{22}$-quinolium(TCNQ) Langmuir- Blodgett(LB) films are reported through a study of current-voltage(I-V) characteristics along a perpendicular direction. The I-V characteristics were investigated by applying a step or a pulse voltage to the specimen as well as changing temperatures in the range of 20-250[.deg. C] It show an ohmic behavior in low-electric field, and a nonohmic behavior in high-electric field. This nonohmic behavior has been interpreted in terms of a conduction mechanism of space-charge limited current and Schottky effect. When the electric field is near the strength of 10$_{6}$ V/cm, there occur anomalous phenomena similar to breakdown. When step or pulse voltage is applied, the breakdown voltage shifts to the higher one as the step or pulse time width becomes shorter. To see the influence of temperature, current was measured as a function of temperature under the several bias voltages, which are lower than that of breakdown. It shows that the current increases to about 103 times near 60-70[.deg. C], and remains constant for a while up to around 150[.deg. C] and then suddenly drops. We have also performed a DSC(differential scanning calorimetry) measurement with $C_{22}$-quinolium(TCNQ) powder in the range of 30-300[.deg. C]. These results imply that the anomalous phenomena occuring in the high electric field are caused by the electrical and internal thermal effect such as a joule heating.ating.

• 전기전자학회논문지
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• 제7권1호
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• pp.22-31
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• 2003

한의학에서 진단과 치료의 기본 대상인 경혈?경락의 혈위 식별을 위한 방법으로 기존의 방식은 직류를 인체 피부에 자극하여 양도점을 식별하고 있다. 그러나 직류는 피부의 저항과 용량성으로 인한 시간에 따른 전류 감소현상을 나타내며, 이러한 시간적 감소현상은 경락진단의 변수로는 유의성을 가지나 식별율 및 부합율, 인체영향력, 재현성 등에서 식별데이터의 신뢰성이 충분하지 못한 단점이 있었다. 이를 개선하기 위하여 1.28V의 4kHz, 듀티비 40%의 구형파인 SPAC(Single Power Alternative Current) 자극방식의 최적 파라메터를 추출하였다. 또한 피부 상태에 관계없이 식별이 어려운 부위에서도 식별이 용이하도록 피부 전류량의 절대값과 상대값을 동시에 표시하고, 측정 전류량을 그래프로 연속 표시하여 식별에 유리하도록 하였다. 추출된 최적파라메터와 알고리즘을 적용한 시스템을 구현하여 경혈자극 방식에 따른 식별율, 재현성, 인체영향력 및 고전 경혈점과의 부합율을 비교하여 성능이 우수함을 확인하였다.

• 조명전기설비학회논문지
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• 제19권1호
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• pp.136-142
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• 2005

본 논문에서는 패러데이 효과(Faraday effect)를 이용한 초고압 전력설비에서의 대전류 측정을 위한 광CT의 온도 특성에 대한 기초연구를 기술하였다. 1310[nm] 레이저 다이오드를 광원으로 사용하고 PIN-Photodiode를 수신부로 사용하고 광의 전송로는 Fiber내에서 편광상태를 유지 할 수 있는 30[m]의 단일 모드 광섬유를 사용하였다. 온도 변환에 따른 실험을 하기 위한 온도변환장치는 알루미늄으로 제작하였다. 전류의 측정은 400[A]에서 1300[A]까지의 범위에서 측정하였으며 온도는 $-40[^{\circ}C]$에서 $50[^{\circ}C]$까지 $10[^{\circ}C]$씩 증가시키면서 측정하였다. 동일한 실험 환경하에서 출력신호는 인가전류가 증가할수록, 주변온도가 높을수록 비례하여 증가하였다.

• Journal of Electrical Engineering and Technology
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• 제9권5호
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• pp.1654-1659
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• 2014

Tunneling field-effect transistors (TFETs) are very applicable to low standby-power application by their virtues of low off-current ($I_{off}$) and small subthreshold swing (S). However, low on-current ($I_{on}$) of silicon-based TFETs has been pointed out as a drawback. To improve $I_{on}$ of TFET, a gate-all-around (GAA) TFET based on III-V compound semiconductor with InAs/InGaAs/InP multiple-heterojunction structure is proposed and investigated. Its performances have been evaluated with the gallium (Ga) composition (x) for $In_{1-x}Ga_xAs$ in the channel region. According to the simulation results for $I_{on}$, $I_{off}$, S, and on/off current ratio ($I_{on}/I_{off}$), the device adopting $In_{0.53}Ga_{0.47}As$ channel showed the optimum direct-current (DC) performance, as a result of controlling the Ga fraction. By introducing an n-type InGaAs thin layer near the source end, improved DC characteristics and radio-frequency (RF) performances were obtained due to boosted band-to-band (BTB) tunneling efficiency.

• 대한의용생체공학회:의공학회지
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• 제41권6호
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• pp.235-246
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• 2020

This study aimed to evaluate the inhibitory effect of micro-current stimulation(MCS) on adipogenesis regarding with Wnt/β-catenin pathway using the ob/ob mouse and 3T3-L1 cell line. 6-week old ob/ob male mice were equally assigned to four groups: obese group(ob), obese with MCS groups(50 μA, 200 μA, and 400 μA). 6-week old C57BL/6J male mice were assigned to the control group(CON). We analyzed abdominal adipose tissue volume by using in vivo micro-CT and measured the body weight, feed intake, liver weight and triglycerides in serum. All the MCS groups showed that significantly reduced body weight and triglycerides in serum. In the case of liver weight and abdominal adipose tissue volume, the inhibitory effect of adipogenesis was shown in the 200 μA and 400 μA groups. To elucidate the anti-obesity effect of MCS, β-catenin, C/EBPα and FAS protein expressions were analyzed by western blotting. β-catenin expression was upregulated, C/EBPα and FAS expression were down-regulated in the relatively high-intensity groups(200 μA and 400 μA). Thus, the 200 μA and 400 μA for the intensity of MCS were chosen for cell experiments. In the 3T3-L1 cell line, Wnt/β-catenin pathway including Wnt10b, Wnt3a, β-catenin and Cyclin D1 was activated in all MCS groups. Accordingly, the expression level of C/EBPα was decreased during the differentiation and lipid droplet was significantly reduced in Oil red O staining results. These results suggest that the Wnt/β-catenin signaling might be activated by MCS with current intensities between 200-400 μA and it may lead to anti-obesity effects.

• Advances in nano research
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• 제17권2호
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• pp.137-147
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• 2024

Graphene nanoribbons (GNRs) are considered a promising alternative to graphene for future nanoelectronic applications. However, GNRs-based device modeling is still at an early stage. This research models the electronic properties of n-doped rough-edged 13-armchair graphene nanoribbons (13-AGNRs) and quantum transport properties of n-doped rough-edged 13-armchair graphene nanoribbon field-effect transistors (13-AGNRFETs) at different doping concentrations. Step-up and edge doping are used to incorporate doping within the nanostructure. The numerical real-space nearest-neighbour tight-binding (NNTB) method constructs the Hamiltonian operator matrix, which computes electronic properties, including the sub-band structure and bandgap. Quantum transport properties are subsequently computed using the self-consistent solution of the two-dimensional Poisson and Schrödinger equations within the non-equilibrium Green's function method. The finite difference method solves the Poisson equation, while the successive over-relaxation method speeds up the convergence process. Performance metrics of the device are then computed. The results show that highly doped, rough-edged 13-AGNRs exhibit a lower bandgap. Moreover, n-doped rough-edged 13-AGNRFETs with a channel of higher doping concentration have better gate control and are less affected by leakage current because they demonstrate a higher current ratio and lower off-current. Furthermore, highly n-doped rough-edged 13-AGNRFETs have better channel control and are less affected by the short channel effect due to the lower value of subthreshold swing and drain-induced barrier lowering. The inclusion of dopants enhances the on-current by introducing more charge carriers in the highly n-doped, rough-edged channel. This research highlights the importance of optimizing doping concentrations for enhancing GNRFET-based device performance, making them viable for applications in nanoelectronics.

• 대한약리학회지
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• 제20권1호
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• pp.23-32
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• 1984

정상 또는 morphine을 처리한 개구리(Rana nigromaculate)의 피부에서 Ussing 등의 방법에 의하여 막전위와 단락전류에 미치는 morphine의 작용과 morphine 작용에 미치는 전해질의 영향을 관찰하여 다음과 같은 성적을 얻었다. 1) Morphine $5{\pm}10^{-3}$은 개구리 피부의 막전위와 단락전류를 현저히 감소시켰으며 약물투여후 60분후에 최고의 효과를 나타냈다. 2) Naloxone $10^{-4}$은 morphine의 막전위 및 단란전류 억제작용을 차단치 못하였다. 3) 영양액내 $Na^+$ 농도감소, $K^+$ 농도증가 및 $Ca^{2+}$농도증가는 morphine의 막전위 및 단란전류 억제작용ㅇ르 현저히 강화하였으며, $Mn^{2+}$첨가는 morphine의 막전위 억제효과만을 강화시켰다. 한편 $Ca^{2+}$ 농도의 감소로써 morphine의 단락전류억제 효과는 현저히 약화되었으며 $Ma^{2+}$농도 감소로써 morphine의 단락전류 억제효과로 더불어 막전위 억제효과도 감약되었다. 4) Morphine 처리 표본에서 막전위와 단락전류는 morphine 처리 초기에 일시적인 감소를 일으킨 후 증가하여 morphine 처리 $4{\sim}8$일에는 대조군에 비하여 현저히 상승하였다. 또한 morphine의 막전위 및 단락전류 억제효과에 있어서도 morphine처리 $1{\sim}2$일에는 morphine의 억제효과가 강화되나 morphine의 처리 4 또는 8일에는 현저히 약화되었다. 이상의 실험성적으로 morphine의 약물내성을 포함한 그 약리적작용이 생체막에서의 전해질수송 또는 전해질 투과성에 영향을 미쳐 초래될 수 있음을 시사하는 것으로 추측하였다.

• Asian-Australasian Journal of Animal Sciences
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• 제29권1호
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• pp.36-42
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• 2016

Milk-related traits (milk yield, fat and protein) have been crucial to selection of Holstein. It is essential to find the current selection trends of Holstein. Despite this, uncovering the current trends of selection have been ignored in previous studies. We suggest a new formula to detect the current selection trends based on single nucleotide polymorphisms (SNP). This suggestion is based on the best linear unbiased prediction (BLUP) and the Fisher's fundamental theorem of natural selection both of which are trait-dependent. Fisher's theorem links the additive genetic variance to the selection coefficient. For Holstein milk production traits, we estimated the additive genetic variance using SNP effect from BLUP and selection coefficients based on genetic variance to search highly selective SNPs. Through these processes, we identified significantly selective SNPs. The number of genes containing highly selective SNPs with p-value <0.01 (nearly top 1% SNPs) in all traits and p-value <0.001 (nearly top 0.1%) in any traits was 14. They are phosphodiesterase 4B (PDE4B), serine/threonine kinase 40 (STK40), collagen, type XI, alpha 1 (COL11A1), ephrin-A1 (EFNA1), netrin 4 (NTN4), neuron specific gene family member 1 (NSG1), estrogen receptor 1 (ESR1), neurexin 3 (NRXN3), spectrin, beta, non-erythrocytic 1 (SPTBN1), ADP-ribosylation factor interacting protein 1 (ARFIP1), mutL homolog 1 (MLH1), transmembrane channel-like 7 (TMC7), carboxypeptidase X, member 2 (CPXM2) and ADAM metallopeptidase domain 12 (ADAM12). These genes may be important for future artificial selection trends. Also, we found that the SNP effect predicted from BLUP was the key factor to determine the expected current selection coefficient of SNP. Under Hardy-Weinberg equilibrium of SNP markers in current generation, the selection coefficient is equivalent to $2^*SNP$ effect.

• The Korean Journal of Physiology
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• 제23권2호
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• pp.313-328
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• 1989

The electrophysiological properties of the inward current contributing to the late plateau phase of the action potential were investigated using the whole cell clamp technique and intracellular dialysis in single atrial cells isolated from the rabbit heart. The inward current was activated by various repolarizing pulses after a brief depolarizing pulse to +40 mV for 2 ms and its time course was similar to that of the late plateau of the action potential. The current was fully activated above the potential of -40 mV and abolished by intracellular EGTA. Ryanodine of $1{\mu}M$ also abolished the late plateau and the inward current. Reduced $Na_o\;to\;30%\;and\;20\;mM\;Na_1$ diminished the late plateau together with the inward current. Diltiazem blocked the activation of the current and Ni in the concentration of $40{\sim}200\;{\mu}M$ decreased the development of the late plateau and the inward current. Fully activated current-voltage relation of the inward current showed exponential voltage dependency which was steeper in more hyperplarizing range. The above findings suggest that the inward current was activated by intracellular calcium and contribute the late plateau phase of the action potential. It could be concluded that the inward current would be the inward component of Na-Ca exchange.